Sound-box diaphragm.



'J. G. ENGLISH. sown BOX DIAPHRAGM. APPLICATION FILED FEB. 2,1912.

1,091,202 Patented Mar. 24, 19m

INVENTOR Z6 JQ/m erg/ ish.

WITNESSES 1 10. I 81 B, :5 MW

UNIT. ED STACEEE OFFICE. l

JOHN o. ENGLISH, or CAMDEN, NEW .Innsnir, ASSIGNOR '10 vrcroa TALKING MACHINE COMPANY, A CORPORATION or NEW JERSEY} soUNnaox DIAPHRAGM.

speciflcation ofletters Patent.

Patented Mar. 24, 1914.

. Application filed February 2, 1912. Serial No. 675,019.

To all whom it may concern:

Be it known that I, JOHN C. ENGLISH, a citizen of the United States, and 'a resident of'Camden, county of Camden, and State of New Jersey, have invented certain new and useful Improvements in Sound-Box, 1s a Diaphragms, of which the followin specification, reference being had to t e accompanying drawing.

This invention particularly relates to vibr'atory diaphragms for sound reproducing devices such as are cooperatively employed in connection with sound reproducing mechanism of a talkin machine.

It is believed t at 'diaphragms, which in themselves are more or less resonant, and emit individual tones peculiar to their materialor structure, produce vibrations which are sympathetic with, and to a considerable extent tend to interfere with tones produced by vibrations effected by sound waves of similar frequency, which it is desired to record, and which tend to cause disturbances which produce unpleasant and disagreeable sensations upon the ear of the bearer in the reproduction of a record.

The principal object of this invention is to provide a diaphragm which tends to obviate the difliculties experienced in diaphragms having an individual resonance by forming the diaphragm of substantially nonresonant material, preferably composed of a subereous formation.

Other objects of this invention are to provide a diaphragm of such extreme lightness and flexibility as to be capable of responding to, and reproducing the most minute and delicate sound waves, with all their overtones, and consequently to produce substantially the full Volume of the original sounds; to provide a diaphragm of such uniformity as to produce substantially perfect recitation or reproduction of the original sounds; to provide a diaphragm formed of such resilient material as to be ca able of being supported without employing gaskets, and prevented from rattling by rigidly engaging its peripheral edge etween the opposed faces of the relatively adjustable members of the sound box; and to provide a diaphragm which will adhere to the faces of the sound box members.

Further objects of this invention are to provide a diaphragm which is formed of a material readily obtainable.', and to provide be cheaply produced in any desired quantity.

llhis invention further includes all of the .varlous novel features of construction and arrangement hereinafter more definitely specified. In the accompanying drawing, Figure 1 1s a face view of a diaphragm conveniently formed in accordance with'this invention; F 1g. 2 is a central transverse sectional view said diaphragm, taken on the line 2-2 in F 1g. 1; Fig. 3 is a view similar to Fig. 2 showing a possible modification of the diaphragm shown in Figs. 1 and 2; Fig. 4 is another form of diaphragm constructed in accordance with this invention, and Fig. 5 is a central transverse sectional view of the diaphragm shown in Fig. 4 taken on the line 55 in said figure. I In said figures, the diaphragm shown in Figs. 1 and 2 comprises a substantially fiat thin disk 10, formed of compressed comminuted subereous material, which is provided with a central aperture'll for the convenient attachment of the free end of a stylus bar, or similar member of any suitable sound reproducing device.

The form of this invention illustrated in Fig. 3 comprises a diaphragm 14 formed of comminuted subereous material, coalesced by compression, and having a substantially thin peripheral edge 15 and a relatively thick central portion l6, preferably formed with a plane surface 17, and a convex surface.18, and being provided-with the usual aperture 19 for engagement of. a stylus bar or equivalent member.

Alth ugh the form of this invention shown n Fig. 3 has itsopposite surfaces realong its peripheral margin 22, with the inher margin 23 of the annulus 20 in any suitable manner, preferably by an adhesive.

While the central web 21 of the diaphragm shown in Figs. 4 and 5 comprises a web of substantially rigid material, such for. instance as stifi' paper, and preferably in order to increase its rigidity without substantially increasing its weight has, a bulged central portion 25, as best shown in Fig. 5, it may be otherwise formed to roduce substantially similar results. he central bulged portion of said diaphragm is provided with the central aperture 26 for the convenient connection of the vibratory member of a suitable sound reproducing device.

The comminuted subereous material may be held together by any suitable binder, such for instance as nitro-cellulose, which permits such flexibility of material when compressed as to permit a diaphragm formed thereof to respond to the most delicate and minute sound waves, and such diaphragm has been found to produce most desirable results, which it is assumed is due to its being formed of'a material which appears to have little or no individual resonance within the range of'ordinary audible sounds. F urthermore, diaphragms constructed in accordance with this invention have been found to reproduce sounds uniformly, that is to say,

in reproducing from the same record differ ent diaphragms reproduce said record with the same clearness and volume, and the reproduction has been found to be'uniform in all respects, which is believed to be due to the fact that such diaphragms formed in accordance with this invention are of uniform texture and consequently are free from. local stresses.

While it is believed that the best results have been attained by the use of a diaphragm formed of a subereous composition, such as comminuted cork, natural cork may be employed with substantially good results, and therefore it is to be understood that-this invention is not to be confined to the specific subereous material hereinbefore referred to, but that any subereous material may be employed, and by the term subereous I mean any similar or equivalent materials to those above referred to, such for instance as comminuted wood or other fibrous material having subereous properties, and furthermore, the comminuted particles may be coalesced without a binder by compression alone. i

It will be observed that sound boxes when provided with a diaphragm formed in the manner above described, which may be supported in a sound box or other suitable de vice without the employment of gaskets, may be assembled at a cost much less than when provided with diaphragms which require a bulged central portion formed of paper,

havingits periphery secured to the inner margin of said annulus.

2. Adiaphragm comprising an annulus of thin highly flexible subereous material, and

a bulged central portion formed of paper 4 having its periphery secured to the inner margin of said annulus by an adhesive.

JOHN C. ENGLISH.

Witnesses:

MARY E. ENGLISH, JoHN D. Myers. 

